Industrial chemicals obtained from inexpensive sources are desirable for use in industrial processes, for example as raw materials, solvents, or starting materials. It has become increasingly desirable to obtain industrial chemicals or their precursors from materials that are not only inexpensive but also benign in the environment. Of particular interest are materials which can be obtained from renewable sources, that is, materials that are produced by a biological activity such as planting, farming, or harvesting. As used herein, the terms “renewable” and “biosourced” can be used interchangeably.
Furan and its derivatives, particularly C5 and C6 furanic compounds such as furfural and 5-hydroxymethyl-2-furfural (HMF, also known as 5-hydroxymethyl-2-furaldehyde), are useful intermediates in the production of fuels and industrial chemicals for use as pharmaceuticals, herbicides, stabilizers, and polymers. For example, HMF can be a useful material for the synthesis of tetrahydrofuran 2,5-dimethanol and 1,6-hexanediol. For cost and environmental reasons, it would desirable to be able to synthesize such compounds from biomass. However, the synthesis of intermediates from biomass often relies on edible feedstock materials. For example, many routes that rely on dehydration of C6 carbohydrates to C5 and C6 furanic materials, such as furfural and HMF, start with glucose and fructose as a feedstock (see R. Karinen et al., ChemSusChem, 4(8), (2011), 1002-1016).
At the highly acidic aqueous environments and high temperatures needed to form HMF from lignocellulose, HMF exhibits a high rate of decomposition to levulinic acid, formic acid, and a significant amount of humin byproducts which are undesirable tar-like materials. A process which allows for the production of HMF in water under close to neutral conditions from a non-food biomass lignocellulose derived material would be highly desirable.
Levoglucosenone, an isomer of HMF, can be produced from woody (lignocellulosic) material through pyrolysis. F. Shafizadeh et al. (Carbohydrate Research, 71, (1979), 169-191) found that heating levoglucosenone in 0.5 M HCl (pH=0.3) in a boiling water bath to reaction completion (2.5 hours) produced HMF in a 16% yield. Heating levoglucosenone in 2 M acetic acid (pH=2.2) produced 1,6-anhydro-3-deoxy-β-D-erythro-hexopyranos-2-ulose, (represented by Formula (I-a)) in a 77% yield, but no HMF.

There remains a need for a route to furanic compounds, such as 5-hydroxymethyl-2-furfural, from non-food biomass-derived compounds such as levoglucosenone that avoids the production of undesired reactive intermediates.